10 research outputs found
Mixer Assembly for a Gas Turbine Engine
A mixer assembly for a gas turbine engine is provided, including a main mixer with fuel injection holes located between at least one radial swirler and at least one axial swirler, wherein the fuel injected into the main mixer is atomized and dispersed by the air flowing through the radial swirler and the axial swirler
Lance L. Smith Advanced Combustor Concepts for Low Emissions Supersonic Propulsion
Novel lean-burn combustor concepts were designed and evaluated for supersonic aircraft propulsion, with a focus on cruise NO x emissions. Premixing to lean conditions is especially challenging at supersonic cruise because combustor inlet temperatures are high and autoignition times are short. However, combustor pressure is significantly lower than at takeoff, so at cruise this allows heated jet fuel to be vaporized before injection as an aid to mixing. Two concepts-differentiated by swirler aerodynamics, swirler size, and staging method-were evaluated in the work reported here, both using injection of vaporized jet fuel. Computational fluid dynamics (CFD) calculations of mixing and combustion were used to design hardware for each concept. Injectors for each were fabricated using stereolithography (SLA) for cold-flow mixing tests, and using metal fabrication for subsequent combustion tests. Combustion test results show that emissions index for NO x (EINO x ) < 5 was achieved for both concepts in single-sector tests at supersonic cruise combustor conditions
A new local density functional for main-group thermochemistry, transition metal bonding, thermochemical kinetics, and noncovalent interactions
Product Module Rig Test
The low emissions potential of a Rich-Quench-Lean (RQL) combustor for use in the High Speed Civil Transport (HSCT) application was evaluated as part of Work Breakdown Structure (WBS) 1.0.2.7 of the NASA Critical Propulsion Components (CPC) Program under Contract NAS3-27235. Combustion testing was conducted in cell 1E of the Jet Burner Test Stand at United Technologies Research Center. Specifically, a Rich-Quench-Lean combustor, utilizing reduced scale quench technology implemented in a quench vane concept in a product-like configuration (Product Module Rig), demonstrated the capability of achieving an emissions index of nitrogen oxides (NOx EI) of 8.5 gm/Kg fuel at the supersonic flight condition (relative to the program goal of 5 gm/Kg fuel). Developmental parametric testing of various quench vane configurations in the more fundamental flametube, Single Module Rig Configuration, demonstrated NOx EI as low as 5.2. All configurations in both the Product Module Rig configuration and the Single Module Rig configuration demonstrated exceptional efficiencies, greater than 99.95 percent, relative to the program goal of 99.9 percent efficiency at supersonic cruise conditions. Sensitivity of emissions to quench orifice design parameters were determined during the parametric quench vane test series in support of the design of the Product Module Rig configuration. For the rectangular quench orifices investigated, an aspect ratio (length/width) of approximately 2 was found to be near optimum. An optimum for orifice spacing was found to exist at approximately 0.167 inches, resulting in 24 orifices per side of a quench vane, for the 0.435 inch quench zone channel height investigated in the Single Module Rig. Smaller quench zone channel heights appeared to be beneficial in reducing emissions. Measurements were also obtained in the Single Module Rig configuration on the sensitivity of emissions to the critical combustor parameters of fuel/air ratio, pressure drop, and residence time. Minimal sensitivity was observed for all of these parameters
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Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33
Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci
A selection of Slovenian literary heroes for the preschool period
V vrtcih slovenske literarne junake vse bolj spodrivajo tuji fantazijski junaki, za katere se otroci navdušijo prek risank, revij in video igric. Slovenski junaki so pomemben del naše kulture in so lahko nekakšni spremljevalci v domovinski vzgoji pri najmlajših. To delo naj služi kot promocija slovenskih literarnih junakov pri otrocih vseh starosti, z začetkom v predšolskem obdobju. V delu je opredeljeno merilo izbire likovpredstavljene so njihove zgodbe, posebne lastnosti in upodobitevjunaki so po izvoru opredeljeni kot ljudski ali umetninavedeni so avtorji in zgodovinske okoliščine nastankaraziskane so njihova prepoznavnost in zastopanost v različnih medijih (slikanice, avdio- in video mediji, oglasi) ter dostopnost teh medijev.In preschools, Slovenian literary heroes are being displaced by foreign fantastic heroes that impress children via cartoons, magazines and video games. Slovenian heroes are an important part of our culture and can act as companions of sorts within citizenship education of youngsters. This thesis should serve as a promotion of Slovenian literary heroes for children of all ages, beginning with the preschool period. The thesis defines the selection criterion of charactersit introduces their stories, special characteristics and depictionsit defines heroes by origin as folk or artificialit lists the authors and historical circumstances of productionit investigates their recognisability and representation in various media (picture books, audio- and video media, advertisements) and the accessibility of these media
Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33
Genome-wide association studies (GWAS) have mapped risk alleles for at
least 10 distinct cancers to a small region of 63 000 bp on chromosome
5p15.33. This region harbors the TERT and CLPTM1L genes; the former
encodes the catalytic subunit of telomerase reverse transcriptase and
the latter may play a role in apoptosis. To investigate further the
genetic architecture of common susceptibility alleles in this region, we
conducted an agnostic subset-based meta-analysis (association analysis
based on subsets) across six distinct cancers in 34 248 cases and 45 036
controls. Based on sequential conditional analysis, we identified as
many as six independent risk loci marked by common single-nucleotide
polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 x
10(-39); Region 3: rs2853677, P = 3.30 x 10(-36) and P-Conditional =
2.36 x 10(-8); Region 4: rs2736098, P = 3.87 x 10(-12) and P-Conditional
= 5.19 x 10(-6), Region 5: rs13172201, P = 0.041 and P-Conditional =
2.04 x 10(-6); and Region 6: rs10069690, P = 7.49 x 10 215 and
P-Conditional = 5.35 x 10(-7)) and one in the neighboring CLPTM1L
gene(Region 2: rs451360; P = 1.90 x 10(-18) and P-Conditional = 7.06 x
10(-16)). Between three and five cancers mapped to each independent
locus with both risk-enhancing and protective effects. Allele-specific
effects on DNA methylation were seen for a subset of risk loci,
indicating that methylation and subsequent effects on gene expression
may contribute to the biology of risk variants on 5p15.33. Our results
provide strong support for extensive pleiotropy across this region of
5p15.33, to an extent not previously observed in other cancer
susceptibility loci